Because these item sets already in the game as a prize, this seems a little unrewarding for a week-long event aimed at transmogrification enthusiasts. However in a Q&A Blizzard has stated that there may be new rewards for further seasons of this event.

Comment by LordSothe

You can only buy the ensemble set for your class. It won't even let you purchase the others.

If you were like me and got extra tokens on your main trying to win the event, they will sadly go to waste (at least for now).

Comment by ModishVision

To start the Trial of Style Micro-holiday you need to visit a main city, and speak with a transmogrifier to queue up for the scenario placing you into a partyOnce it begins you will see what the chosen theme is for the scenario, while giving you two minutes to prepare your transmog.You will notice you can change your transmog, and also get a quick trim using a barber chair on either side of the room.

When it begins there will be a countdown, and two players will be selected to go against each other.Simply decide which one you like better and vote!

When it is your turn to be on the stage you are able to grab more attention by pressing either of these 3 buttonsWaveCheerDance